We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
Types of Visual Aids and Their Uses
85
so the width of the picture runs along the film, the top and bottom of the ordinary scene being toward the edge of the film, as illustrated page 86. This means that the double-frame filmslide ordinarily runs through the projector horizontally. An exception occurs whenever a vertical picture has been taken, as of a tree or high waterfall, by turning the camera vertically. This necessitates turning the aperture gate of the projector to a vertical position to present the image in proper position on the screen. This should not be done by the seemingly simple expedient of turning the projector on its side, as modern projection lamps are made to burn base down, and most of them will burn out more readily if placed in any other position. Thus a more versatile projector, a swivel-head type, is required for double-frame filmslides.
The rapid growth of the private use of miniature cameras with double-frame exposure on 35 mm. negative is bringing the double-frame filmslide into widespread use in presenting the visual phases of special projects. Also the very important work of the library associations in many parts of the world, in arranging for the making and exchange of miniature photographs (on filmslides) of the pages of rare books and manuscripts, promises to result in the production of enormous quantities of doubleframe filmslides. (See page 96.)
An important variation of filmslide practice and production has already grown to useful proportions. We refer to the mounting and preservation of individual frames clipped from filmslides. This is done either between stiff cardboard masks or between miniature glass slides 2" x 2" square. Certain filmslide projectors* are fitted with miniature slide carriers so these indivi
Photo Courtesy Society for Visual Education, Inc.
Section of a 35 mm.
Single -Frame Filmstrip
(Actual Size)
* Argus Models A and B; Eastman; Leica; S.V.E. Tri-Purpose Models AAA, DD, and CC; and S.V.E. Miniature Models AK, DK, and RK for 2"x2" slides only.